STUDY ON PHASE-SEPARATION OF PMMA/SAN BLENDS INDUCED BY GLASS BEADS THROUGH DYNAMIC RHEOLOGICAL MEASUREMENTS

Based on the premise that the addition of glass beads （GB） could hardly influence the linear viscoelasticity in low frequency （ω） region for homogeneous polymer systems, the dynamic rheological behaviors of unfilled and filled poly（methyl methyacrylate） （PMMA）/poly（styrene-co-acrylonitrile） （SAN） blends were studied in order to explore the effect of GB on the phase-separation of binary polymer matrix. Results show that GB has an induced effect on the phase-separation, which embodies that the phase-separation temperature （Ts） of PMMA/SAN blend filled with GB is lower than that of the unfilled system. The higher content of GB, the higher is the ＂secondary plateau＂ of ω in the terminal region of storage modulus （G＇） versus ω plot. The ＂secondary plateau＂ appearing in the terminal region is attributed to the phase-separation of PMMA/SAN blends and it becomes more fiat for filled polymer blends under the same conditions. However, it is suggested that this kind of ＂induced effect＂ is related to the GB content; the higher content of GB particles might enhance the interaction between the particles and polymer matrix. Moreover, it is found that the addition of GB also has an influence more or less on the morphology and domain size of polymer matrix. It is believed that the plot of dynamic viscosity （η＇） versus the loss viscosity （η＂） is sensitive to examine the effect induced by GB on the phase-separation of binary polymer matrix.

Effects of hemoperfusion combined with hemodialysis on target organ damage in patients with acute paraquat poisoning

Objective: To investigate the effects of hemoperfusion combined with hemodialysis on target organ damage in patients with acute paraquat poisoning. Methods: A total of 42 patients with acute paraquat poisoning who were admitted and treated in our hospital between December 2013 and October 2017 were selected as the research subjects, and their therapies were reviewed and used to divide them into the control group (n=20) who received hemoperfusion alone and the combined treatment group (n=22) who received hemoperfusion combined with hemodialysis. The differences in the levels of liver and kidney function indexes in peripheral blood as well as lung function indexes in arterial blood were compared between the two groups of patients immediately after admission, after 1 d of treatment and after 3 d of treatment. Results: Immediately after admission, the differences in the levels of liver and kidney function indexes in peripheral blood as well as lung function indexes in arterial blood were not statistically significant between the two groups. After 1d of treatment and after 3 d of treatment, kidney function indexes Scr, BUN and β2-MG levels in peripheral blood of combined treatment group were lower than those of control group at corresponding time points respectively;liver function indexes ALT, AST, TB and ALP levels in peripheral blood were lower than those of control group at corresponding time points respectively;lung function indexes PaO2, BE and PCO3- levels in arterial blood were higher than those of control group at corresponding time points respectively whereas PaCO2 levels were lower than those of control group at corresponding time points respectively. Conclusion: Compared with hemoperfusion alone, hemoperfusion combined with hemodialysis is more advantageous in protecting the functions of liver, kidney, lungs and other target organs of patients with acute paraquat poisoning.

A quantitative method for storm surge vulnerability assessment – a case study of Weihai city

In traditional vulnerability assessments,a synthetic index method is usually used to select all types of social and economic indexes so that more aspects can be covered;however,the requisite social and economic data are not always available or are not highly relevant to the studied geographical space,which makes it difficult to conduct quantitative calculations.In this paper,a spatial value density assessment method was developed to improve the hazard of place model.First,a three-dimensional(3D)model of a coastal city was obtained using oblique airborne photogrammetry and image-based 3D reconstruction and then,architecture footprints were employed to extract the geometric information of each individual building.Additionally,a vulnerability assessment system was established to quantitatively account for the aggregate economic value of a selected set of urban surface features.Using geographic information system(GIS)techniques,the aggregate value of these urban features within each geographic unit can be accurately calculated to quantify the exposure and vulnerability of coastal cities to storm surge.A vulnerability assessment was conducted using Weihai city as an example.The study shows that vulnerability assessment accuracy was greatly improved by downscaling the assessment granularity from county-level administrative districts to a 1-km grid.